Pollution characteristics and health risk assessment of phthalate esters in agricultural soil and vegetables in the Yangtze River Delta of China.

As an important environmental reservoir of phthalate esters (PAEs), soil-plant system constitutes a key exposure pathway to human health. In this study, agricultural soil and vegetable samples were collected from the Yangtze River Delta (approximately 211,700 km2), one of the most developed regions in China, to determine the contamination characteristics of priority PAEs. The total concentrations of six PAEs ranged from 5.42 to 1580 ng·g-1 dry weight in soils and from 10.9 to 16,400 ng·g-1 dry weight in vegetables. Di-(2-ethylhexyl) phthalate (DEHP) accounted for 88.3% and 61.9% of the total PAEs in soils and vegetables, respectively. The spatial distribution of PAEs in the soils was as follows: Shanghai city (70.8-1583 ng·g-1 dw) > Anhui province (46.8-1530 ng·g-1 dw) > Jiangsu province (14.4-558 ng·g-1 dw) > Zhejiang province (5.40-488 ng·g-1 dw). Non-cancer risks exist for adults and children in 6.5% and 7.8% of the sites, respectively. Carcinogenic risks were regarded unacceptable in 5.6% and 1.3% of the sites for adults and children, respectively. The bioconcentration factor (BCF) of PAEs showed positive correlation with lipid content of vegetables. A basic reference of the lipid-content threshold to guarantee the safety of leafy vegetables was proposed based on partition-limited model. We suggested to cultivate vegetables with lipid content <0.21% in most heavily contaminated area in the region. This study provides information for effectively controlling PAEs contamination in soil-plant system in developed districts.